This topic illustrates how to filter ASPxTreeList data nodes using a column's header filter.
Column headers can display filter buttons. Clicking a filter button invokes a filter dropdown, which lists unique values within a column, and enables you to apply filter criteria against this column. These buttons are hidden by default. To show filter buttons, set the TreeListSettings.ShowHeaderFilterButton property to true. You can control filter button visibility for individual columns using a column's TreeListDataColumn.AllowHeaderFilter property.
Note that if a filter is applied to a column, other column header filters display unique values of the sorted nodes. To show the full list of values (include values of rows hidden by sorting), hold down SHIFT and click a header filter button.
The following two list modes are available for all tree list columns.
List. The header filter's filter items are displayed as a regular list. Clicking an item invokes a corresponding action and automatically closes the dropdown.
CheckedList. The header filter's filter items are displayed as a checked list. In this mode, an end-user can select multiple items simultaneously. When the drop-down window is closed by clicking the OK button, the grid will display those records that contain checked values.
The following two list modes are available for date columns only.
The ASPxTreeList header filter allows using HTML tags in an item text. This example demonstrates how to set numbers in bold by using HTML tags within an item's format pattern. The image below shows the result.